Abstract

The continuous grey scale image is printed on the liquid crystal(LC) cell through the similar printing process on a photographic paper. The LC cell is prepared with a rubbed photo-cross-linkable polymer coated substrate whose azimuthal anchoring strength increases by exposing the unpolarized UV light. The cell filled with the LC is exposed to the UV light through a negative film, and is thermally developed and fixed. The twist angle continuously changes from 0° to about 90° by increasing the exposure, and the positive image with continuous grey levels appears in the LC cell between parallel polarizers.